Adverse effects of thyroid dysfunction on pregnancy and pregnancy outcome: Epidemiologic study in Slovenia

Global and regional incidence of intrahepatic cholestasis of pregnancy: a systematic review and meta-analysis

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) can be a source of significant distress for both pregnant women and the fetus, impairing the quality of life and well-being of pregnant women, leading to psychological disorders among pregnant women with severe or recurrent ICP, and causing life-threatening complications among fetuses. Regrettably, our current understanding of ICP globally is limited, lacking a comprehensive estimation of its incidence. Therefore, in this systematic review and meta-analysis, we aimed to investigate the global and regional incidence of ICP and identify factors that account for its variety across studies.

METHODS

A comprehensive search strategy was implemented across PubMed, Scopus, and Web of Science databases. To stabilize the variance, the Freeman-Tukey double arcsine transformation was employed. Subgroup analyses were conducted based on continent, publication type, study design and timing, regional classifications, developmental status, and World Bank income grouping. A multivariate meta-regression analysis was performed to estimate the effects of the continuous moderators on the effect size.

RESULTS

A total of 42,972,872 pregnant women were analyzed from 302 studies. The overall pooled incidence [95% confidence interval] of ICP was 2.9% [2.5, 3.3]. Studies with larger sample sizes tended to provide significantly lower estimates of ICP incidence: 1.6% [1.3, 2] vs 4.7% [3.9, 5.5]. Asia had the highest incidence of ICP among the continents, whereas Oceania had the lowest. Countries that were classified as developed and with higher income had a lower incidence of ICP than those classified as developing and low and middle income.

CONCLUSIONS

The findings of this study will provide valuable insights into the current knowledge regarding the association of the quality of public health and socioeconomic variations with the incidence of ICP on a global scale.

Prepregnancy Hypothyroidism versus Gestational Hypothyroidism: A Comparative Study

INTRODUCTION

Hypothyroidism managed inadequately in pregnancy may have grave outcomes for both mother and baby. Understanding pregnancy outcomes in our country with low awareness about thyroid diseases is important.

OBJECTIVES

The objectives of the study were to evaluate demographic features and biochemical parameters in patients with prepregnancy hypothyroidism versus patients diagnosed to have primary hypothyroidism during pregnancy and to assess pregnancy outcomes.

STUDY DESIGN

Prospective design.

MATERIALS AND METHODS

The study was conducted in a tertiary care center in Bengaluru for 2 years. The patients were divided into two groups - Group I: Prepregnancy hypothyroidism and Group II: Hypothyroid during pregnancy. They were further staged according to ESI guidelines as subclinical or overt hypothyroidism.

STATISTICAL ANALYSIS

Chi-square and Mann-Whitney test.

RESULTS

A total of 452 pregnant women with hypothyroidism were analyzed. The data of 371 delivered pregnancies were available. Group I and II had 196 (43.36%) and 256 (56.64%) patients, respectively. Age at presentation (years) was 27.09 ± 4.19 in Group I versus 25.74 ± 4.29 in Group II (P = 0.003); gestational age (weeks) was 9.04 ± 5.41 in Group I versus 13.81 ± 9.12 in Group II (P = 0.000). There was one case of congenital hypothyroidism in baby in each group. Mean birth weight was 2.90 ± 0.39 kg in Group I versus 2.88 ± 0.36 kg in Group II; P = 0.608. There were four abortions in Group I versus ten in Group II (P = 0.231), 104 cesarean sections in Group I compared to 133 in Group II; (P = 0.382). There was no difference in number of cesarean sections, abortions and low birth weight babies between overt and subclinical hypothyroidism subgroups.

CONCLUSIONS

Group I patients presented earlier for testing suggesting awareness was good in this group. There was no difference in pregnancy outcome between the two groups. Overt versus subclinical status did not have any different effects on pregnancy outcomes in any group.

Maternal Thyroid Disease and Preterm Birth: Systematic Review and Meta-Analysis

CONTEXT

Thyroid disease in pregnancy is increasing with rising average maternal ages in developed countries. The evidence for an association between preterm birth and thyroid disease has been confounded by small studies with varying outcomes and methodology.

OBJECTIVE

The aim of this meta-analysis is to review the literature regarding thyroid disease including subclinical and overt hypothyroidism, hyperthyroidism, and isolated hypothyroxinemia and the specific outcome of preterm birth.

DATA SOURCES

A search of PubMed and Embase databases was performed in May 2015. A fixed-effects model was used to calculate the overall combined odds ratio (OR) with its corresponding 95% confidence interval (95% CI) to evaluate the relationship between thyroid disease and preterm delivery.

STUDY SELECTION

Studies were considered eligible if they met the following criteria: prospective cohort study or a case control study; the exposure of interest was maternal thyroid disease, including subclinical hypothyroidism, overt hypothyroidism, hyperthyroidism, or isolated hypothyroxinemia; the outcome of interest was preterm delivery; and data regarding numbers of preterm births in each cohort were reported.

DATA EXTRACTION

Data were recorded in a database evidence table including any incidence data for maternal thyroid disease and preterm birth compared to a reference group.

DATA SYNTHESIS

Fourteen cohort studies and one case control study involving 2 532 704 participants were included. The combined OR of preterm delivery for pregnant women with overt hypothyroidism compared with the reference group was 1.19 (95% CI, 1.12-1.26; P < .00001). There was also a significant risk of preterm birth in women with hyperthyroidism (OR, 1.24 [95%, CI 1.17-1.31]; P < .00001). Subclinical hypothyroidism and isolated hypothyroxinemia showed no significant increase in OR. Sensitivity analysis made no change to these results.

CONCLUSION

Both overt hypothyroidism and hyperthyroidism are associated with a small but statistically significant increase in OR for preterm birth not seen in subclinical hypothyroidism or isolated hypothyroxinemia.

Neonatal outcomes and birth weight in pregnancies complicated by maternal thyroid disease

Maternal hypothyroidism has previously been shown to increase risk for neonatal intensive care treatment, but otherwise the association between thyroid diseases and neonatal morbidity is understudied. The Consortium on Safe Labor, a retrospective cohort (2002-2008), included 223,512 singleton deliveries of which 0.2% had hyperthyroidism, 1.4% primary and 0.1% iatrogenic hypothyroidism, and 1.3% other/unspecified thyroid disease. Logistic regression with generalized estimating equations estimated adjusted odds ratios of adverse outcomes. Intensive care treatment was more common for neonates of women with thyroid disease. Hyperthyroidism and primary hypothyroidism were associated with sepsis, respiratory distress syndrome, transient tachypnea, and apnea. Iatrogenic hypothyroidism was associated with sepsis and neonatal anemia. Hyperthyroidism was also associated with rare outcomes (prevalence, <1%) including cardiomyopathy, retinopathy of prematurity, and neonatal thyroid diseases. Hyperthyroid non-Hispanic black women had higher odds of term infants that weighed <2,500 g, and hypothyroid non-Hispanic white women had higher odds of large-for-gestational-age infants. These analyses were stratified by race/ethnicity due to interaction. Associations were similar in analyses restricted to term infants. In conclusion, thyroid diseases were associated with increased neonatal morbidity. Although we lacked data on treatment during pregnancy, these nationwide data suggest a need for better thyroid disease management to reduce neonatal morbidity.

Thyroid hormone replacement in women of reproductive age: is surgeon knowledge related to operative volume?

BACKGROUND

It is not known if surgeons who place women of reproductive age on thyroid hormone replacement (levothyroxine, LT4) routinely inform them of the increased LT4 demands with future pregnancy. In addition, it is not clear whether reading the 2007 Endocrine Society's "Guidelines on the Management of Thyroid Dysfunction during Pregnancy and Postpartum" influences the role of the surgeon in patient education. The objective of this study was to identify the role of the surgeon in patient education at the time of initiation of LT4 therapy.

METHODS

A two-sided one-page survey was distributed to the 260 surgeons attending the 2009 American Association of Endocrine Surgeons' meeting. Of those distributed, 109 (42%) surgeons returned the survey.

RESULTS

Although only 26/109 (23%) read the 2007 Endocrine Society's "Guidelines on the Management of Thyroid Dysfunction during Pregnancy and Postpartum," reading the guidelines was associated with a significantly greater likelihood of informing patients of higher LT4 requirements with pregnancy (p < 0.0001). Eighty-five percent of those who read the guidelines "often" or "always" informed patients of higher LT4 requirements with future pregnancy, whereas only 44% of those who did not read the guidelines provided the same level of education. After controlling for surgeon sex, academic versus private practice, years in practice, and number of surgeries performed in 2008, the only independent predictor of patient education was reading the guidelines (p = 0.006). On multivariable analysis, surgeon volume was associated with reading the guidelines (p = 0.006). The mean number of thyroid surgeries performed by those who read the guidelines versus those who did not was 164.46 +/- 16.98 versus 115.01 +/- 8.27 (p = 0.005).

CONCLUSION

Surgeons who read the Endocrine Society's "Guidelines on the Management of Thyroid Dysfunction during Pregnancy and Postpartum" were significantly more likely to inform patients of the need for higher LT4 doses with pregnancy. Thyroid surgery volume was associated with guideline awareness.

Universal screening versus case finding for detection and treatment of thyroid hormonal dysfunction during pregnancy

CONTEXT

Thyroid disease during pregnancy has been associated with multiple adverse outcomes. Whether all women should be screened for thyroid disease during pregnancy is controversial.

OBJECTIVE

The objective of the study was to determine whether treatment of thyroid disease during pregnancy decreases the incidence of adverse outcomes and compare the ability of universal screening vs. case finding in detecting thyroid dysfunction.

DESIGN

Women in the first trimester were randomly assigned to the universal screening group or case-finding group. Women in both groups were stratified as high risk or low risk based on risk factors for thyroid disease. All women in the universal screening group, and high-risk women in the case-finding group, were immediately tested for free T(4), TSH, and thyroid peroxidase antibody. Low-risk women in the case-finding group had their sera tested postpartum.

SETTING

The study was conducted at two ambulatory clinics of community hospitals in southern Italy.

PATIENTS

A total of 4562 women were randomly assigned to the universal screening or case-finding group.

INTERVENTION

Intervention included levothyroxine in women with a TSH above 2.5 mIU/liter in TPO antibody-positive women and antithyroid medication in women with a undetectable TSH and elevated free T(4).

MAIN OUTCOME MEASURE

Total number of adverse obstetrical and neonatal outcomes was measured.

RESULTS

No significant differences were seen in adverse outcomes between the case-finding and universal screening groups. Adverse outcomes were less likely to occur among low-risk women in the screening group than those in the case-finding group.

CONCLUSIONS

Universal screening compared with case finding did not result in a decrease in adverse outcomes. Treatment of hypothyroidism or hyperthyroidism identified by screening a low-risk group was associated with a lower rate of adverse outcomes.

The role of clinical guidelines in patient care: thyroid hormone replacement in women of reproductive age

BACKGROUND

Clinical guidelines have a role in medical education and in the standardization of patient care. However, it is not clear whether guidelines created by subspecialists reach relevant practicing physicians or influence patient care. In 2007 the Endocrine Society released "Guidelines on the Management of Thyroid Dysfunction During Pregnancy and Postpartum." The objective of this study was to characterize the role of these guidelines in provider education and in subsequent patient care decisions.

METHOD

In 2009 three waves of mail surveys were distributed to 1601 Wisconsin health care providers with a history of providing obstetric care. Survey participants were members of the American College of Obstetricians and Gynecologists or the American Academy of Family Physicians. There were 881 returned surveys (55%) and 575 were eligible for the study (adjusted rate 52.5%).

RESULTS

Although only 11.5% of providers read the Endocrine Society's guidelines, reading the guidelines was associated with increased likelihood of prepregnancy counseling on levothyroxine management (p < 0.0001), increased likelihood of screening for thyroid disease risk factors (p = 0.0007), and increased likelihood of empiric levothyroxine dose increase in pregnant patients (p = 0.0005). After controlling for provider sex, membership affiliation, practice setting, and number of years in practice, reading the guidelines was still an independent predictor of patient education prepregnancy (p < 0.01).

CONCLUSION

The Endocrine Society's "Guidelines on the Management of Thyroid Dysfunction During Pregnancy and Postpartum" reached a minority of providers involved in obstetrics, but exposure to the guidelines did impact patient care. A multidisciplinary approach to guideline creation would improve the dissemination and practical application of guidelines.

Maternal thyroid disease and preterm delivery

CONTEXT

Preterm delivery is the leading cause of perinatal morbidity and mortality in the United States, and its incidence is increasing. The present manuscript reviews the literature on the relationship of hypothyroidism and/or autoimmune thyroid disease to preterm delivery.

EVIDENCE ACQUISITION

A PubMed search was used to identify all relevant articles. A reference search of all retrieved articles was undertaken. All articles identified in the search were included in the review.

EVIDENCE SYNTHESIS

Uncontrolled case series were discussed in the manuscript but not included in drawing conclusions from the literature.

CONCLUSIONS

Hypothyroidism and autoimmune thyroid disease in euthyroid women are associated with preterm delivery. A single intervention trial has documented a dramatic decrease in the incidence of preterm delivery in thyroid antibody-positive women treated with levothyroxine. Confirmatory studies are needed before universal screening and intervention can be recommended.